Rotary internal combustion engine



lAug'. 4, 1931.

I Filed April 19,

1929 5 Sheets-Sheet l Aug. ,4,1A 1931.

P. J. ASHWORTH ROTARY INTERNAL COMBUSTION ENGINE Filed April 19, 1929 n 4, "w47 f-- ?Z .W .70 fa ya f7 l ff 6a i zi z? A in 5 Sheets-Sheet 2 v Aug, 4, 1931.l P. J. AsHwoR'rl-l 1.817663 ROTARY INTERNAL COMBUSTION-ENGINE Filed April 19, 1929 SG/SheetS-Shveet 4 Aug. 4, 1931. P. J. AsHwoRTH l)817,663

ROTARYJNTERNAL coMBusTloN ENGINE Filed April 19, 1929 5 sheets-*sheet 5 a 4f W2 /z/ 1% ff Pateted Aug. 4, 1931 @s i; momies-@omg miem femm@ RDTAR'Y CMB'USTIl-ON ppl-icatiowlled-Apil 19;1929; Seriall N0. 356,51Sl

the mm1@ of ope *zi-fhig at this point' in the opeintioii Fig", lis'o View showing the' position' of the' meer fte? therig of the charge with the exhaust valve open and the intake-valve closed;

Fig. 14 illustrates the position of the valve operating cams at this point of the operation of the motor; and

Fig. 15 is a sectional detailed view of the cam-mechanism taken on line 15-15 of Fig. 1, showing the arrangement of the cams and the push-rods for operating the valves.

The present invention embraces, in general, an engine or motor having an annular rotor mounted within a cylindrical casing and provided with stepped faces which co-operate with corresponding faces on an end head to open and close a plurality of combustionchambers as the rotor turns and is given an axial sliding movement; means for admitting the charge into the combustion-chambers, eX- ploding it, and scavenging the burned gases; and means for rotatively connecting the rotor with an axial power-output shaft to be'driven therefrom.

Referring to the drawings, the invention is herein illustrated by way of example as embodied in a motor having four intake-valves combined with an equal number of associated exhaust-valves so arranged that two power impulses are applied to the rotor during cach revolution thereof at points equidistantly spaced about its axis. It is to be understood, however, that the form of construction of the motor may be varied at will to embody a greater or less number of valve units in accordance with requirements. As shown most clearly in Figs. l and 2, the main casing o f the motor may be constructed in the form of a flanged cylinder 2 having heads 3 and 4 at its ends secured in place by bolts 5 and 6 extending through the flanges.

The end-head 3 is constituted by a substantially fiat disk or plate having a central recessed hub 7 braced by ribs 8 and adapted to receive suitable bearings for the axial power-shaft 10. Preferably, the hub 7 is counterbored at 9 to adapt it to receive inner and outer annular races 11 and l2, between which are balls 13 providing friction-reducing journals for the shaft 10. rlhe inner races 11 may be forced onto the reduced end 14 of the shaft which projects through the axial opening in the end of the hub 7, While the outer race 12 may be made in two sections held together' by a flanged casing 15 forced into the bore 9 of the hub 7, this being a usual construction for bearings of the present type.

The power-shaft 10 carries a drive-element 2O which, as herein shown, is constructed in the form of a dished plate or spider 21 supported from a central hub 22. The hub 22 is `secured rotatively to the shaft 10 by any suitable means such as the spline and key shown at 23 in Fi 2. As shown most clearly in Fig. 4, the drive-member 2O is provided with an annular rim 24 formed with two opposite slots or openings 25 which are adapted to receive driving connections, to be later described, carried on the rotor 30 and adapted to play in the slots as the rotor oscillates axially Within the casing 2. At the end of the hub 22 of the drive-member 2O is a flat thrust-washer 26 fastened in place by screws 27 and adapted to bear against the bearing races 1,1 and 12 to take the end thrust of the shaft 10 in one direction.

The head 4 which clos-es the opposite end of the casing` or cylinder 2 is provided with valve openings and carries the valve-operating mechanism. As shown most clearly in Figs. 2 and 3, the head 4 comprises tWo separate parts7 its main portion consisting of an annular plate fastened to the flanges of the cylinder 2 by the bolts 6 previously mentioned. Fastened to the inner rim of the annulus 4 by means of bolts 29 is a central recessed member or closure 31 which is formed with a hub 32 carrying a bearing for the axial power-shaft 10, and also an inner annular bearing wall 33 for the rotor 30. `he bearing hub 32 is braced from the annular wall 33 by radial ribs 34 to stiifen the structure of this part. Housed Within the end of the hub 32 are inner and outer annular ballraces 35 and 3G, similar in construction to the races at the opposite end of the shaft, between which run the balls 37. The inner race 35 abuts a shoulder 38 on the shaft l() at one side and bears against the end of the hub 32 to take the end thrust of the shaft in this direction. F astened to the end of the bearing hub 32 by means of bolts 39 is a cap or oil retainer 40 provided with a pocket for receiving lubricant. Surrounding the shaft l0 Within the cavity of the cap 40 is an oil ring 41 which distributes the lubricant around the bearing.

rEhe enlarged portion of the shaft 10 inwardly beyond the shoulder 38 carries the cams 44 and 45 for operating the valvemechanism to be later described. The cams 44 and 45 are keyed to the shaft 10 at 46 and 47 and held in place axially thereof against the inner ball-race 35 by means of a collar 48 screwed onto a threaded portion 49 of the shaft. It is noted here that the shaft 10 is preferably tubular or of hollow construction to render it light in weight, particularly to adapt it for use as the propeller shaft of an airplane. Its end which projects fromI the bearing 32 may be tapered as shown to adapt it to receive the hub of the propeller and provided With a suitable threaded portion for the nut which fastens the propeller in place. rlhe opposite end of the shaft 10 is shown as provided with a stud 51 having an enlarged portion 52 screwed into its bore. The projecting stud-shaft 51 may be employed for carrying a pulley, gears or the like for driving the magneto, oil pump and other appurtenances to the motor.

The cylindrical wall 33 of the end-closure llmese;

' shaped rotor 30 rotates. As shovvn more particula'rly in Fig. 2, the Wall of the casing 2' may be counterbored to receive a relatively thin lining sleeve 53 of Wear-resisting mate-V rial. As'also shoWn'in this vievv, the rotor 30 is of hollow constructionA to render it light in Weight, and let into its inner Wall is a lining sleeve 54C of bronze or Babbitt metal. The outer compression-rings 55 corresponding to the pistonlrings of reciprocating motors and serving for the same purpose to seal the joint to prevent loss of compression. Similar compression-rings 55 are held in recesses or grooves' on the cylindrical bearing Wall vvhich conforms to the inner face of the rotor 30.

It has been noted that the rotor 30 is oonnected'to the' drive-member Q0 by means engaging in its slots 25. Preferably, such means are ofthe anti-friction type and, as shown in Figs. 2 and Il, they may comprise ball-bearing rollers 57. The outer rim of the rotor 30 is provided at its bottom With a thickened Wall 58 Which is drilled to receive hollow studs or spindles 59 projecting through holes in the opposite Wall. Two of these spindles are provided, they being arranged radially of the axis of the rotor to ca-rry ball-races GO fast thereon, between which' and the outer annular rollers 57 are balls Gli Th'erollers57' may be constructed in the form of races similar to those previ-k ously described, being free to turn on the balls 61; the rotor 30 being thus connected to rotate the member-'20 to drive the shaft 10 and this connection being adapted to alloiv thel oscillating movement of the rotor in the direction of its axis as the rollers 57 slide in the slots25. y

Referring now particularly to /land' 3, the* annular rotor 30'is` con. tructed in a novel andpeculiar manner to adapt lit to cooperate vwith one of the end-heads of the cylinder 2 whereby, during its rotation, it opens and closes pockets fonstituting combustionchambe'rs into which the charge of fuel is drawn, compressed, and exploded to apply thepropulsive force to the rotor. As shown in Figs. i and 5, the opposite sides of the rotort) aire of undulatory configuration, bc` ing'provided with inclined stepped faces of a predetermined angularity with respect to a plane perpendicular to its axis of the rotor.

In the present embodiment there are fourl steps or ises' on each side of the rotor com- `orising the relatively long, slightly inclined faces G5 and the shorter, more abrupt faces 66 on' one side, andthe similarly inclined long faces and short' faces 68 on the oppo` site side; Each side of the rotor thusV divided radially into four Wedgeshaped' sections, the highlpoint's' 69'onv one side coinciding with or beingrarranged'opposite tothe lovv points 7 O on the other side. The inclined' faces and 66 co-'ope'rate With-similarly inclined faces 7l and 72 provided onthe' in teriorof the annular en`dhead et to openland close pocket-s, indicated at 73, which constitute the combustion-chambers in the manner and for' the purpose as hereinafter more fullyrexi'slainedi The longer inclined faces G5 on the rotor are complementary to the faces 7lonthe heads to adapt them to ride thereagai-nst' and slide thereon. the rotor 3G turns Aon its axis and is caused to oscillate in the direction of its axis due to this engrigen'ient. The shorter fac-s (36 Aon the' rotor 30 are offslightly less inclinationl than the opposite faces 72' on the bcad l so that normally Withthe rotor in the position as shown in Fig. il these twofaces will not conform.

notlierv Words, openings 73 are leftbetween thefaces'G` and faces 72 and these register with the ports? 82 in the head of the motor, see' Fig. 6, to provide for drawing the chargesinto the combustion' chambers the latter' a're iucreasedtin size by the turning of the rotor in the direction indicated by the arrow in Fig. 4;. combustion side of the rotor 30 is closed across its full Width, the stops 65 and G6 bridging the space between its inner and out'- er Walls. On the other hand, the oppositel side of' the rotor is partly open with the steps 67 and 68 formed on the edge of thev thickened Wall 58.

The' purpose of formino' the opposite side of the rotor SO'With an` undulatory surface corresponding to that of the combustion side is to provide' cam-faces 'co-operating with suitablev bearingsl to maintain the rotor with its faces 65'substantially in contact With-the faces 7l`on the head 4. As herein illustrated, the end thrust-bearings for the rotor 30 comprise rotatable rollers `journaled on the' interior Walls of the casing 2 as shown in ride thereon. The rollers 75 may be of the same construction as'the rollers 57 vvhich'connectthe rotor with the drive-member' Q0, be-

ing constituted as' annular races turning on l It is here noted that th-e with the faces 7l on the head fl, but a great- (er number may be employed if desired inV combustion side of the rotor 30 meet in sharp points, on its opposite side of the cam-faces 67 and 68 are oined v ith a rounding contour to adapt them to ride smoothly over the vollers 75.

Referring now to lligs. 1, l and 6, the intakeand eriaust-valves for the motor are of dual arniigen'ient, there being a single opeiiing or port S2 in the head el for each :et oi.E valves. ris shown in Fig. 3, the head l is provided with integral, annular bosses 83 projecting therefrom at intervals around its circumference, there being four of these bosses for the embodiment of: the invention as herein illustrated. rlhe circular openings 31 within the bosses 33 con'nnunicate with the ports 32 opening` through the head d and are adapted to receive valve-housings 85 suitably secured therein. As shown in Figs. 1 and 6, 'he valve-housings 35 have flanges 81 litted to the openings 84, there being a separate valve-housing applied to each side of the boss 83. The valve-housings 35 are clamped in place on opposite sides oi' the bosses 83 by .neans of bolts 36 and S7. Suitable gaskets, not herein shown, may be employed for sealH ing the joints between the valve-housings 85 and the bosses 83. The bolts 36 extend clear through the outer walls of the housings S5 .Vith nuts S3 at their ends, while the bolts 87 are ot' different construction to adapt them to serve as the supporting-posts for the rockerarins which operate the valves. As shown in Fig. 1, each bolt 37 has a shouldered portion E9 abutting the flanged foot 90 of one housing and a nut 91 screwed against the similar foot or the opposite housing.

All of the valve-housings 35 are of the same construction, being provided with quill-like viearings 92 for the stems 93 of the valves which have the usual mushroom heads 94. rlhe heads 9i oi? the vaives are formed with beveled rims to adaptthem to seat in the beveled recesses 95 in the flanges 86 of the 'iousings 35. For the sake of convenience of description the intake-valve in general is designated 98 and the `enhaust-valve 99. It will be noted by reference to Fig. 1 that the interior passage through the valve-housings 35 fire oi L-shape and the openings thereof are directed outwardly at the circumference of the head 4 and provided with flanges 100. rThe i receive suitable studs 101. for bolting them to the .flanges oit' suitable intake and exhaust inaniiiolds not herein illustrated. rl`he intake and exhaust manifolds may comprise arcuately-shaped pipe having flanged openings connected respectively to the flanges 100 of the intake-valve 98 and the exhaust-valve 99. rlh-e intake manifold may be connected with a carburetor or other suitable fuel-mixing device, and the exhaust manifold may have. a connection leading to the atmosphere at any convenient location. These parts are not nges 100 are drilled and threaded toV herein illustrated as they may be of any preferred construction and arrangement as well known to those versed in the art.

On the ends of the valve-stems 93 are circular disks or caps 103 secured in place by nuts 104;. Compressed between the caps 103 and the ends ol. the valve-stem bearings 92 are flat spiral springs 105 which normally tend to maintain the heads of the Valves closed against their seats 95.

The valves are operated by means of rocker-arms 107 which carry rollers 103 bearing against the ends of the valve-stems 93 to adapt them to slide the latter against the pressure of the springs 105. The rocker-arms 107 are pivoted on studs 109 carried in forked bearii 110 which are screwed onto the ends ofz the bolts or posts 87, previously referred to, and secured in fixed position by checknnts 111. lt is noted here that the dual valves 93 and 99 of each set are vdisposed in alternate relation around the endhead d so that two intake-valves are located in adjacent relation and likewise two exhaust-valves are adjacent. The purpose of tais arrangement is to provide intake .arves may be operated from a single push-rod or piuiiger; and likewise the rockerarms for the adjoining exhaust-valves may be actuated from a single plunger so that in the pres-ent construction only four push-rods or plungers are required for actuating the eight if'alves. The rocker-arms 107 have tail-portions 112 which ext-end in opposite directions to cross each other in overlying relation. At the ends of the tail-portions 112 are hubs 113 bored to receive set-screws 111i which are provided witli recessed or cupped ends. The cupped ends 115 of the set-screws 114 receive the rounded ends of link-pins or rods 116 connected to the push-rods 117 in the manner as later explained.

The push-rods 117 are of a novel and peculiar construction as next described. Screwed through threaded holes in the cylindrical wall of the hub 32 are tubular or cylindrical guides 118 formed with shoulders 119 which abut thc ouJ er surface of the hub. The push-rods 117 which slide in the guides 118 are preferably of hollow7 or tubular construction, their inner ends being slotted to receive rollers 120 which turn on pintles or trunnions 121 held in bearings at the sides of the slots. Inserted in the opposite ends of the push-rods 117 are stu-ds 122 formed with overhanging flanged heads 123. The heads 123 have depending skirts 12d enclosing the outside of the guides 118 and provided with projecting annular flanges 125 which are formed with depressions or sockets 126 for receiving the rounded ends of the links 116 which, as previously explained, are correspondingly connected to the rocker-arms 107. 1t will be understood that as the push-rods 117 slide in their guides that the rocker-arms for two adjacent- 118 under the action of the cams 44 and 45A bearing against their rollers 120 the links 116 will be caused to exert a thrust on the ends of the rocker-,arms 107 to actuate the latter in the manner as later more fully ex- 'plained The set-screws 114 which engage the ends of the links 116 are adjustable to maintain a tight connection between theA different plane from that of the push-rods for the exhaust-Valves 99. Through this arrangement the push-rods fO-r the intakevalves are alined with the cam 45, while the push-rods for the exhaust-valves are disposed opposite the cam 44 so that the pairs of rocker-arms 107 which are arranged diametrically opposite each other on the head 4 are actuated in one case from o-ne cam and in the other instance by the other cam, see Fig. 1. Referring to this latter view, the cam 45 for the intake-valves is provided with two opposite high points 129 having relative` ly long bearing faces; whereas the cam 44 for the exhaust-valves is provide-d with opposite high points `130 of sharper contour. The purpose of this difference in the construction of the cams will be later set forth in connection wi h the explanation of' the method of operation of the Valves. Y

The means lfor firing or detonating the charge drawn into the combustion-chambers may comprise suitable spark-plugs connected Y to a magneto or other make-and-break device for the electrical current. As shown in Figs. 3` and' 6 the spark-plugs 131 are screwed into threaded bores extending through bosses or hubs 132 on the outer face of the end-head 4, a plug being provided adjacent each set of valves. The bores for the spark-plugs 131 intersect the wall of the head 4 on the shorter inclined fac-es 72 on its interior s0 that the sparking Ypoins 133 of the plugs are disposed adjacent to the pockets 73 formed by these faces and the co-'operating faces 66 on the rotor 30, see Fig. 6. Conductors 134 connected to the firing-pins of the plugs 131 at 135 may be joined in a cable and led to the circuit-breaker or magneto which is placed at any convenient location in accordance with the use to which the motor is put, these connections not being Vherein shown in 'detail as they may be of anv preferred arrangement.

The construction and arrangement of the essential parts of a motor exemplifying the present invention having now been described in detail, its method of operation will next be explained in connection with the diagrammatic'view's, Figs'7 to 14. 'llig? illustrates the rotor 30 at the point in its revolution when` the charge is about to be drawn into the combustion-chambers. For convenience of description the functioning will be explained in connection with one combustion-chamber only, it being'funderstood that it is the same for all of them. It will be noted by reference to Fig. 7 that the exhaust-valve 99 is closed and the intake-valve 98 opened, the cams 44 and 45 being positioned in relation to the push-rod rollers 120 as shown in Fig. 8. As

here illustrated, the opposite high points 129 on the cam 45 are turned into position beneath the rollers 120 on the push-rods 117 to slide the latter as shown in'Fig. 1 whereby the rocker-arms 107 are moved to depress the` valve-stems 93 to open all of the intake-valves 98 to admit the charge from the carburetor down through the ports 82. At this juncture the rollers 120 on the push-rods 117 forl rotor in the direction indicated by the arrow y V98 ride off from the high points 129 on the,

cam 45V and these valves -are closed by the action of their springs. During this part of the revolution of the rotor 30 the long inclined faces 67 on its opposite side ride on the rollers 75 as the rotor is given a slight motion in the direction of its axis which causes it to recede from the head 4. Then as the motor continues to turn its sharper inclined faces 68 ride against the rollers 75 and the rotor will be oscillated in the opposite direction or toward the head 4 to effect what may be termed a compression stroke. During this axial movement of the rotor 30 its steps 65 move toward the correspondingly inclined faces 71 on the head 4 so vthat the charge in the combustion-chambers is compressed within the confines of the relatively narrow spaces between the succeeding shorter faces 66 on the rotor and the faces 72 on the head, see Fig. 11, the compression of the charge also taking place in the ports 82 and between the ends of the closed valve-heads 94.

At this point the charge is fired by the spark from the plug 131 through suitable control at the circuit-breaker or magneto operated in the usual manner. As the charge is explodedin each combustion-chamber a powtheeh'argesl'in an, of several' com:

bustion chambers may be exploded lat substantially Vthe same instant or .with a progressive ltiming if desired. As the rotor is turnedunder the propulsive force ofthe severalv explosions it again recedes from the head 4 Awith its cam-faces 67 riding down the rollers 75 until it reaches the position illustratedY in Fig. 13. At this juncture the severalexhaast-valves 99 are opened by the action of the high points 130 on the cam 44 asshown in Fig. 14. The axial motion of the rotor 30 is now reversed as the faces G8 `on its cam side ride against the rollers 7 5 and the next movement of the rotor 'toward the head 4 -fserves as a scavenging stroke to `expel the burned gases from the combustion-chambers. That is to say` as the faces 65 on therotor close against the corresponding faces 71 on the inside of the head 4 the residueof burned gases in the combustion-chambers will be 'forced out through the Aports 82 and exhaustvalves '.99.

At the end of the scavenging stroke the rotor l0 will have been carried into the position illustrated in Fig. 7 again, whereupon the exhaust-valves 99 are closed and the intake-valves 98 opened andthe same cycle of operations as just desc ibed is repeated with the rotor drawing a fresh charge into the fcombnstion-chambers and Vcompressing the same, after which the spark-plugs explode the charge to apply thepropulsive force to continue the turniiigmovement of the roto-r. With thenpresent .form of construction of-the invention the propulsive force is applied to the rotor at two points during eachcomplete rotation of the latter while the rotor oscillates to a slight extent in .the direction of its axis or toward and away from the cylinder head 4.

'The speed of the motor may be controlled in the usual way by means of Ia throttle atthe carburetor crier fuel supplyingdevice.

The rotative movementot' the rotor 30 .is communi cated to the power-shaft lOthrougli the medium of the driven-member 2O connected to the` rotor bymeans of the-rollers 57 engaging in its slots or openings 25. As beforeexplained, this form of construction provides `for the oscillating' 4movement ofthe rotor, but it is to be understood that any other suitable rconstruction of the driving connection between the rotor `and the shaft ma v be employed.

lt-is to be particularly noted that'the propulsive force OVenerated bythe explosion .of -he fuel in the combustion-chambers is applied to the rotor at or near its circumference so that the leverage-on-the power-.shaft is in proportion to the size .of the motor, and not restricted by limitations of space as inthe case oitl-ie crank-shaft of the ordinary reciprocating en fine. 'in other words, the propulsive force of the powerimpulse is applied with afmaxinium leverage, and this leverage maintained constant.. Stated briefly, since the propulsive force is always exerted at the saine distance from the axis of the rotor it remains constant as distinguished from the conditions in reciprocating engines employing crank-shafts. W ith the usual crankshaft the leverage of the turning force increases from Zero at the beginning of the powerstroke to the maximum at the quarter or ninety degrees beyond the vertical, and from this point the leverage is reduced again to Zero at the bottom of the stroke. It will be apparent therefore that the present construction of a motor embodying a. rotor on which the power impulse is applied with a practically constant turning force provides greater efficiency over the reciprocating type of motor.

Another feature of improvement in the present invention results from the fact that the propulsive force is continuous in the direct-ion of rotation of the driven part. in the reciprocating type of engine the pistons must come to a dead stop at the end of each stro-ke and their direction of movement be reversed. ln the present improved motor there is no reversal in the direction of movement of the going parts, the power being applied with a smooth, even flow inasmuch as the rotor is always moving at a high speed at the moment of impact of the propulsive force on its steps. In the reciprocating type of motor the piston is stationary, or approximately so, at the movement of impact ofthe p-ropulsive force and its movement must be started gradually and brought up to maxinum speed during one half of the power stroke. rlhis limitation of the reciprocating type of motor has a retarding effect againstthe power impulse. Stated lorieiy, there is no dead conter in the present type of motor so that the power impulse is applied to much greater advantage and the power flow maintained more constant and uniform without acceleration and retardation. Furthermore, the effect of moment-um and inertia on the moving parts is practically nil.

As another advantage the usual heavy flywheel necessary for the reci ai'ocating type of motor may-be dispensed with and the other parts of the motor correspondingly reduced in weight. The elimination of reciprocating pistons, connecting rods and 'the like in- .creasesthe power output of the motor in proportion to the amount of fuel consumed since there is practically no power absorbed in moving or lifting weight at high speed, which in the reciprocating engine may amount to many pounds per minute. ln the present motor the valves are operated from cams onthepower-shaft thus eliminat' the usual separate cam-shaft `and its dri ,g connections. The reduction in the num-ber of o- `erating parts as compared with the multigreater economy in cost and the .saving of 5. A rotary motor comprising a cylinder haring innei` and outer concentric walls forming an annular raceway, a head at one end of the cylinder provided with stepped faces inclined at an angle to a plane perpendicular to its axis and projecting into the raceway, an annular rotor rotatable in the raceway and provided with stepped faces disposed in opposite arrangement to the faces on the head whereby the turning of the rotor will cause an oscillating movement to be imparted thereto to open and close combustion-chambers between its faces and the faces on the head, means to introduce a charge of fuel int-o the combustion-chambers, and means to explode the charge to apply a propulsive force against the stepped faces of the rotor to rotate the latter.

6. A rotary motor comprising a cylindrical casing having inner and outer concentric walls forming an annular' raceway, a head at the end of said casing having stepped faces on its interior inclined at an angle to a plane perpendicular to the axis of the casing, an annular rotor rotatable in the raceway and provided with stepped faces disposed in opposite relation to the inclined faces on the head and also having corresponding cam-faces on its opposite side, bearings engaging against the cam-'faces for taking the axial thrust of the rotor as it is given an axial oscillating motion during its rotation7 means for admittir, g a charge of fuel into the spaces between the inclined faces of the head and rotor as the latter turns in the casing, and means to explode the charge to apply a propulsive forte to rotate the rotor.

7. A rotary engine comprising a cylindrical casing, a head at the end of said casing, stepped faces on the interior of the head inclined at an angle to a plane perpendicular to the axis of the casing, a rotor rotatable within the csaing and provided with inclined faces corresponding to the stepped faces on the head, the opposite side of the rotor being provided with inclined cam-faces substantially complemental to the faces on the other side, roller-bearings engaging said camfaces to adapt the rotor to oscillate axially during its rotation in the casing, means for introducing` a charge of fuel into the spaces opened between the faces of the rotor and head as the rotor turns and oscillates in the casing, and means to explode the charge to apply a propulsive force on the stepped faces of the rotor to turn the latter.

8. A rotary engine comprising' a casing having inner and outer concentric walls forming an annular raceway with a series of faces on its interior inclined at an angle to a plane perpendicular to its axis and alternating with other faces of greater inclination, an annular rotor rotatable in the casing and formed with a series of stepped faces substantially corresponding to these on .interi-nr et thereafter said combustion-chambers are substantially closed to compress the charge of fuel introduced thereinto, means for introducing the charge of fuel into the combustion-chambers and means for exploding the charge to apply a propulsive force against the stepped faces of the rotor to rotate the latter.

9. ln a rotary motor, the combination of a casing having inner and outer concentric walls forming an annular raceway on its interior an annular rotor rotatable in said raceway and provided with stepped faces on its side, means closing one end of the annular raceway and provided with stepped faces arranged substantially complementary to the stepped faces on the rotor whereby when the rotor turns and is caused to oscillate axially in the casing combustion-chambers are opened between its faces and those at the end of the raceway, means for introducing a charge of fuel into the combustion-chambers, and means for exploding the charge to apply a propulsive force against the stepped faces of the rotor to rotate the latter.

10. In a rotary motor, the combination of a casing having inner and outer concentric walls forming an annular raceway, an axial power-shaft journaled in bearings in said casing, a rotor rotatable in the raceway and provided with inclined stepped faces on its side, a head on the casing having inclined stepped faces arranged substantially complementary to the stepped faces on the rotor to adapt the latter to ride thereover to impart an axial oscillating motion to the rotor as it turns in the raceway whereby to cause certain of its faces to recede from those on the head to open combustion-chambers therebetween, means for introducing a charge of fuel into the combustion-chambers, means for exploding the charge to apply a propulsive force on the rotor to turn the latter, and means for rotatively connecting the rotor with the power-shaft.

ll. In a rotary motor, the combination of a. casing formed with an annular raceway on its interior, ahead closing one end of the raceway and provided with stepped faces, a rotor rotatable in the raceway and provided with stepped faces corresponding to those on the head, a power-shaft extending axially of the casing and jou'rnaled in bearings therein, a drive-member keyed to said shaft and provided with an annular rim formed with slots, rollers on the rotor engaging the slots in the drive-member to connect it rotatively with the rotor while adapting the latter to oscillate axially with respect thereto, means for introducing a charge of fuel into the spellings between the stepped faces the head and the rotor when the latter is rotated, and means for exploding t-he charges to apply a propulsive force on the rotor to turn the latter.

12. ln a rotary motor, the combination of a casing having inner and outer concentric walls forming an annular raceway with aseries of stepped faces on its interior, an annular rotor rotatable in said raceway and provided with a series of stepped faces co-operating with 'those on the inerior of the raceway whereby during its rotation it opens and closes combustion-chainbers between the faces7 intake-valves for admitting a charge of fuel into the combustion-chambers as the latter are opened by the rotation of the rotor, means for firing the charge in the combustion-chambers as the latter are closed during the rotation of the rotor to apply a propulsive force thereto, and exhaust-valves for exhausting` the burned gases from the combustionchambers after the force of the explosion is spent.

13. ln a rotary motor, the combination of a casing having inner and outer concentric walls forming` an annular raceway with stepped faces on its interior, an annular rotor rotatable in the casing and provided with stepped faces co-operating with the faces on the interior of the raceway to open and close combustion-chambers therebetween during the rotation of the rotor, intake-valves for admitting a charge of fuel to the combustionchambers, means for exploding the charge in the combustion-chambers to apply a propulsive force against the steps on the rotor, exhaust-valves for exhausting the burned gases from the combustion-chambers after the force of the explosion is spent, and means operated from the rotation of the rotor to open and close the valves in predetermined order.

14. In a. rotary motor, the combination of a casing having inner and outer concentric walls forming an annular raceway with stepped faces on its interior, an annular rotor rotatable in the raceway and provided with stepped faces adapted to co-operate with those on the interior of the raceway to open and close combustion-chambers between the faces, intake-valves for admitting a charge of fuel to the combustion-chambers, means for exploding the charge to apply a propulsive force on the rotor, exhaust-valves for eX- hausting the combnstion-chambers, a powershaft driven from the rotor, and cams on the power-shaft for operating the valves to open and close the latter in predetermined order.

15.V In a rotary motor, the combination of a casing having inner and outer concentric walls forming an annular raceway, an axial power-shaft journaled in bearings in said casing, an annular rotor rotatable in the raceway and provided with stepped faces on its side, a head1' on the easingihaving stepped faces adaptedl to 'co-operate with those on the roterito-'formcombustion-chambers therebetween when the rotor is rotated',`intakevalves--for'admit a cli-arge ef fuel into the e'embustiorr-chamibers, means for -e-xjgaloding thefc'harge in) the combustiion-chambers to lypropu-l's-iv-e forcel te tl-'ie rotor, enhaust- )valves commun ting with the combusti-en- 'chambers'to` exil-must' the burned gases the-refrein, and cams-on the power-shaft adapted to-ac't enthe valvesto. open and close the l'atter Sin predetermined order.

1&6. 'Inl aro-tary meter, :ft-casing having inner and outer concentric walls forming an 'anrniliar -r-a\eeway, an a-nnuilar roto-r rotatable in the raceway and providedw'itlr-stepped. faces, a head on the casing having stepped fac-es ce-ol'aeratin-g with those on.v the rotorwhereby to form combustiron-claambers` between the faces as the rotor is rotated, saidV head-being provided witl "parts vcomm'unicating with thev combustion-chambers, iz-nt'akeand exhaust-valves opening from said ports, rocker-arms for operating'tlireintalreand eXlliaus-t-val-ves,-nae ans for exploding .the charge' introduced intiethe combustion-chambers through the intakevalves: 4to apply a propulsi-ve force on' the roter, a power-shaft dri-ven from the rotor, cams on the poirier-shaft, and plunger-s loperated from saidcams to a-ctuate the rockerarms isotopen and close they valves in predetermined order. i v '17. in a rotary-motorfthe combination of ical casing', a head onthe casing provi d. with stepped faces. on its interior, a rotor rotatable 'in the easing and havin-g' stepped faces col-.operating with `those-en the head to 'form combr-ustion'-chambersas the rotoris: rotated thelcasing", a' series of ports arranged at. interval's` aroundftlie' hea-d incommunicatiorrwith the steps on itsinteV :or,'a pair of intakeand exhaust-valves communicating 4with eac'hf .por-t, means' operate@ rom the rotation of the rotorpto open the .rntailfeevalves toaclmit. a .charge .of fuel into the combustion-chambers, means to explode the charge in the combustion-chambers to apply a propulsive force lto rotate the rotor, means to actuate the exhaust-valves to exhaust the combustion-chambers after the explosion of the charge, rocker-arms for actuating the valves, a push-rod for actuating the rockerarms for two adjacent intake-valves, a cam for sliding said push-rod, a push-rod for operating the rocker-arms for two adjacent eX- haust-valves, and a second cam for sliding the last named push-rod.

18. In a rotary engine, the combination of a casing, a rotor rotatable within the casing and formed to co-operate therewith to form combustion-chambers, a series of ports disposed around the casing in communication with the combustion-chambers therein, an

the combination of intake-valve on one side of each port, an eX- haust-valve on the opposite side of each port, said valves arranged in pairs With tvvo intakeand tWo exhaust-valves in adjacent relationship, pairs of adjacent rocker-arms for operating the valves, a single push-rod for operating each pair of rocker-arms, a cam for operating the push-rods for the intake-valves, and a second cam for operating the push-rods for the exhaust-valves.

19. In a rotary engine, the combination of a casing having opposite concentric Walls forming an annular raceway, an annular rotor rotatable Within the racevvay and adapted to co-operate therewith to form combustion-chambers, a port for each combustion-chamber, bosses on the casing formed With openings leading to the ports, valvehousings inserted into the openings in the bosses on opposite sides thereof, Valves slid able Within the housings, and means to operate the valves during the rotation of the rotor to admit a charge of fuel into the combustion-chambers and to exhaust the burned gases therefrom.

20. In a rotary motor, the combination of a cylindrical casing having opposite concentric Walls forming an annular raceway, a head on said casing having stepped faces projecting into the raceivay, an annular rotor rotatable Within the raceWay land provided with stepped faces co-operating with the faces on the head to form combustion-chambers, ports leading through the head into the combustioirchambers, bosses on the head having circular openings, valve-housings having flanges inserted into the openings in the bosses and arranged in opposed relation, bolts for clamping the housings in place against the bosses, valves slidable in the housings, and means for operating the valves to admit a chargeof fuel into the combustionchambers and to exhaust the burned gases therefrom.

In testimony whereof I hereunto aflix my signature.

PERCY J. ASHVORTH. 

